I am against it except in extreme cases and I do think that the possibility of executing innocent people is a good reason to be against it, but I've never quite understood why finally finding a concrete case of wrongful execution is quite such a big deal. If we're executing a bunch of people I think it's bound to happen.
But it is a big deal and it seems like they have found a case in America. This article is brilliant and horrifying. I didn't think that the cast of CSI were working on these murder cases, but the stuff that went on is truly shocking. Apparently the fact that the guy had posters of Iron Maiden and Led Zepplin (!!) in his room showed that he had a fascination with violence and death. The arson investigators basically knew nothing and a real expert saying as much wasn't enough to convince the Board of Pardons and Paroles to grant him a stay of execution. The governor also refused to grant a stay of execution claiming his decision was "based on the facts of the case."
If it's a topic that you feel passionate about, you should really take the time to read it.